I. Technical Field
The present invention relates to a support for a torque converter of an automatic transmission, and more particularly to a support for a torque converter impeller hub of an automatic transmission which does not require a support bearing.
II. Discussion
In traditional automatic transmissions, an input sleeve from the torque converter called an impeller hub, provides piloting and support for the torque converter and also provides the required rotational energy to drive the pump drive gear, which is splined to the torque converter input sleeve. The pump, in turn, uses this rotational energy to generate flow and pressure which is supplied to a system of valves for controlling cooling and gear shifting. The pump housing also acts to support the torque converter and maintain its position while under gravitational and centrifugal loads. Since the torque converter impeller hub, which supports the torque converter, rotates relative to the pump housing, a needle or roller bearing is typically positioned between these elements to allow support of the torque converter while reducing frictional loss and wear due to this relative movement.
However, the cost of bearings, including purchase or manufacturing and installation, is typically high. As such, this added element increases the overall cost of the transmission. It is also a source of noise. In an attempt to eliminate the use of a bearing element between the impeller hub and the pump housing, a bushing has been used in place of the bearing as a frictional wear element. However, similar to the bearing, the bushing adds an extra element to the transmission thereby increasing its overall cost. Moreover, the bushing tends to wear, creating maintenance and repair problems in the transmission. The present invention was developed in light of these drawbacks.
The present invention overcomes the aforementioned drawbacks, among others, by providing a torque converter support for an automatic transmission which uses a driving gear of a fluid pump to support the torque converter impeller hub. The driving gear is piloted and supported via the journal area in the pump housing. The torque converter impeller hub which is attached to the torque converter, is splined to the driving gear and has at least one rib therearound. A hollow bore of the drive gear rides against the rib, offering radial support to the torque converter impeller hub and torque converter. The drive gear also has a hub. The drive gear hub has an outer surface which forms the journal for the drive gear and it rides against the bore in the pump housing which provides the base support for the system.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.